/** initialize css counter */
#sidebar-content {
    counter-reset: outlineH2Counter;
}

.outline-h2 {
    counter-reset: outlineH3Counter;
}

.outline-h3 {
    counter-reset: outlineH4Counter;
}

.outline-h4 {
    counter-reset: outlineH5Counter;
}

.outline-h5 {
    counter-reset: outlineH6Counter;
}

#sidebar-content .outline-h2 .outline-label::before {
    content: counter(outlineH2Counter) ".";
    counter-increment: outlineH2Counter;
    color: var(--counter-color);
    font-size: 1.3em;
    font-weight: 900;
}

#sidebar-content .outline-h3 .outline-label::before {
    content: counter(outlineH2Counter) "." counter(outlineH3Counter) ".";
    counter-increment: outlineH3Counter;
    color:  var(--counter-color);
    font-size: 1.3em;
    font-weight: 900;
}

#sidebar-content .outline-h4 .outline-label::before {
    content: counter(outlineH2Counter) "." counter(outlineH3Counter) "." counter(outlineH4Counter) ".";
    counter-increment: outlineH4Counter;
    color:  var(--counter-color);
    font-size: 1.3em;
    font-weight: 900;
}

#sidebar-content .outline-h5 .outline-label::before {
    content: counter(outlineH2Counter) "." counter(outlineH3Counter) "." counter(outlineH4Counter) "." counter(outlineH5Counter) ".";
    counter-increment: outlineH5Counter;
    color:  var(--counter-color);
    font-size: 1.3em;
    font-weight: 900;
}

#sidebar-content .outline-h6 .outline-label::before {
    content: counter(outlineH2Counter) "." counter(outlineH3Counter) "." counter(outlineH4Counter) "." counter(outlineH5Counter) "." counter(outlineH6Counter) ".";
    counter-increment: outlineH6Counter;
    color:  var(--counter-color);
    font-size: 1.3em;
    font-weight: 900;
}